package server;

import org.dom4j.*;
import org.dom4j.io.SAXReader;
import server.mapper.ContextMapper;
import server.mapper.HostMapper;
import server.mapper.Mapper;
import server.mapper.WrapperMapper;

import java.io.*;
import java.net.*;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * Minicat的主类
 */
public class Bootstrap {

    /**定义socket监听的端口号*/
    private int port = 8080;

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    private Mapper mapper;

    /**
     * Minicat启动需要初始化展开的一些操作
     */
    public void start() throws Exception {

        // 加载解析相关的配置，web.xml
//        loadServlet();
        loadServer();


        // 定义一个线程池
        int corePoolSize = 10;
        int maximumPoolSize =50;
        long keepAliveTime = 100L;
        TimeUnit unit = TimeUnit.SECONDS;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(50);
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();


        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                corePoolSize,
                maximumPoolSize,
                keepAliveTime,
                unit,
                workQueue,
                threadFactory,
                handler
        );





        /*
            完成Minicat 1.0版本
            需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
         */
        ServerSocket serverSocket = new ServerSocket(port);
        System.out.println("=====>>>Minicat start on port：" + port);

        /*while(true) {
            Socket socket = serverSocket.accept();
            // 有了socket，接收到请求，获取输出流
            OutputStream outputStream = socket.getOutputStream();
            String data = "Hello Minicat!";
            String responseText = HttpProtocolUtil.getHttpHeader200(data.getBytes().length) + data;
            outputStream.write(responseText.getBytes());
            socket.close();
        }*/


        /**
         * 完成Minicat 2.0版本
         * 需求：封装Request和Response对象，返回html静态资源文件
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            response.outputHtml(request.getUrl());
            socket.close();

        }*/


        /**
         * 完成Minicat 3.0版本
         * 需求：可以请求动态资源（Servlet）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            InputStream inputStream = socket.getInputStream();

            // 封装Request对象和Response对象
            Request request = new Request(inputStream);
            Response response = new Response(socket.getOutputStream());

            // 静态资源处理
            if(servletMap.get(request.getUrl()) == null) {
                response.outputHtml(request.getUrl());
            }else{
                // 动态资源servlet请求
                HttpServlet httpServlet = servletMap.get(request.getUrl());
                httpServlet.service(request,response);
            }

            socket.close();

        }
*/

        /*
            多线程改造（不使用线程池）
         */
        /*while(true) {
            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap);
            requestProcessor.start();
        }*/



        System.out.println("=========>>>>>>使用线程池进行多线程改造");
        /*
            多线程改造（使用线程池）
         */
        while(true) {

            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket,servletMap,mapper);
            //requestProcessor.start();
            threadPoolExecutor.execute(requestProcessor);
        }



    }


    private Map<String,HttpServlet> servletMap = new HashMap<String,HttpServlet>();

//    /**
//     * 加载解析web.xml，初始化Servlet
//     */
//    private void loadServlet() {
//        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("web.xml");
//        loadServlet(null,null,"/",resourceAsStream);
//    }


    private void loadServer(){
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("server.xml");
        SAXReader saxReader = new SAXReader();

        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();

            Element connector = (Element) rootElement.selectSingleNode("//Connector");
            Attribute port = connector.attribute("port");
            this.port = Integer.parseInt(port.getStringValue());


            this.mapper =  new Mapper();

            List<Element> hosts = rootElement.selectNodes("//Host");

            for (Element host : hosts) {
                Attribute appBase = host.attribute("appBase");
                Attribute name = host.attribute("name");

                HostMapper hostMapper = new HostMapper();
                mapper.addMapping(name.getStringValue(),hostMapper);

                File file = new File(appBase.getStringValue());
                if (file.isDirectory()){
                    File[] appDirectorys = file.listFiles();
                    for (File appDirectory : appDirectorys) {
                        ContextMapper contextMapper = new ContextMapper();
                        hostMapper.addMapping(appDirectory.getName(),contextMapper);

                        String webxml = appDirectory.getAbsolutePath() + File.separator + "web.xml";
                        loadServlet(contextMapper,appBase.getStringValue(),appDirectory.getName(),new FileInputStream(new File(webxml)));
                    }
                }
            }
        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }

    private void loadServlet(ContextMapper contextMapper,String appBase,String appName,InputStream resourceAsStream) {
        SAXReader saxReader = new SAXReader();

        try {
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();

            List<Element> selectNodes = rootElement.selectNodes("//servlet");
            for (int i = 0; i < selectNodes.size(); i++) {
                Element element =  selectNodes.get(i);
                // <servlet-name>lagou</servlet-name>
                Element servletnameElement = (Element) element.selectSingleNode("servlet-name");
                String servletName = servletnameElement.getStringValue();
                // <servlet-class>server.LagouServlet</servlet-class>
                Element servletclassElement = (Element) element.selectSingleNode("servlet-class");
                String servletClass = servletclassElement.getStringValue();


                // 根据servlet-name的值找到url-pattern
                Element servletMapping = (Element) rootElement.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                // /lagou
                String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();

                URLClassLoader classLoader = URLClassLoader.newInstance(new URL[]{new File(appBase).toURI().toURL()});
                WrapperMapper wrapperMapper = new WrapperMapper();
                wrapperMapper.setHttpServlet((HttpServlet) Class.forName(servletClass, true, classLoader).newInstance());
                contextMapper.addMapping(urlPattern,wrapperMapper);

//                if (null != appBase){
//                    URLClassLoader classLoader = URLClassLoader.newInstance(new URL[]{new File(appBase).toURI().toURL()});
//                    servletMap.put("/" + appName + urlPattern, (HttpServlet) Class.forName(servletClass, true, classLoader).newInstance());
//                } else {
//                    servletMap.put(urlPattern, (HttpServlet) Class.forName(servletClass).newInstance());
//                }
            }



        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

    }

    /**
     * Minicat 的程序启动入口
     * @param args
     */
    public static void main(String[] args) {
        Bootstrap bootstrap = new Bootstrap();
        try {
            // 启动Minicat
            bootstrap.start();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
